What is the meaning of PRN order in medicine administration?

Correct option is C

PRN stands for pro re nata, a Latin phrase meaning "as needed." In medical administration, it refers to medications that are given when the patient requires them, rather than at scheduled times. This is common for pain relievers, antiemetics, or sleep aids. The nurse must assess the need before administering a PRN drug.
Explanation of options: (a) ✘ Post meal, before sleep – This refers to scheduled timing, not the “as-needed” nature of PRN. (b) ✘ Administered immediately – This describes a STAT order, not a PRN order. (c) ✔ When required – Correct meaning of PRN; administered based on patient’s symptoms or needs. (d) ✘ Single administration – Single-dose medication orders are given once but are not necessarily PRN.